1. Field of the Invention
The present invention relates to a method for manufacturing a plurality of completely circular semiconductor substrates (wafers).
2. Description of the Related Art
Generally, in order to specify a crystal orientation of a semiconductor wafer, an orientation flat or a notch is provided. This will be explained later, in detail. Such a wafer is, however, not completely circular due to the presence of the orientation flat or notch. As a result, manufacturing yield is reduced.
In order to increase manufacturing yield, completely circular semiconductor wafers have been adopted (see: JP-A-2-34906 & JP-A-5-13290).
In a prior art method for manufacturing completely circular semiconductor wafers, first, a crystal orientation of each of the wafers is determined by a X-ray diffraction method or the like. Then, each of the wafers is mounted on a laser marking apparatus or the like, thus forming a recognition mark on each of the wafers. Therefore, the number of steps required for determination of crystal orientation is remarkably increased which increases the manufacturing cost. This will also be explained later, in detail.